Theorem mp1i

Description: Inference detaching an antecedent and introducing a new one. (Contributed by Stefan O'Rear, 29-Jan-2015)

	Ref	Expression
Hypotheses	mp1i.1	|- ph
	mp1i.2	|- ( ph -> ps )
Assertion	mp1i	|- ( ch -> ps )

Proof

Step	Hyp	Ref	Expression
1		mp1i.1	|- ph
2		mp1i.2	|- ( ph -> ps )
3	1 2	ax-mp	|- ps
4	3	a1i	|- ( ch -> ps )